$ git clone -n https://src.fedoraproject.org/rpms/mpich.git /var/lib/mock/f40-build-2673841-67655/root/chroot_tmpdir/scmroot/mpich
Cloning into '/var/lib/mock/f40-build-2673841-67655/root/chroot_tmpdir/scmroot/mpich'...
$ git fetch origin 8ab714f2c67838aab53c0b9c5f87396b2ca33c46:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mpich
 * [new ref]         8ab714f2c67838aab53c0b9c5f87396b2ca33c46 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8ab714f Properly check valgrind arches